1. Field of the Invention
The present invention relates to a process for preparing a tacky polyolefin film by using a composition comprising a polyolefin resin, a low grade polyolefin and a tackifier.
2. Description of the Prior Art
Tacky films have been used as food packaging films such as household wrapping film, business use stretchable film and masking films for decorated plates, steel plates and the like. Such tacky films have been widely used. However, the conventional wrapping films and stretchable films are mainly made of vinyl chloride type resins such as polyvinyl chloride or polyvinylidene chloride as the main component. These chlorine-containing resins are not easily combustible whereby the films are not easily disposed. Moreover, toxic gas is generated in the combustion and the preparation of these films. Recently, these problems have been seriously considered.
Accordingly, the development of tacky films by using a non-chlorine type resin has been attempted. When a polyolefin resin is used, a large amount of a tackifier must be incorporated for imparting a desirable tackiness because the polyolefin resin has no tackiness. However, when a large amount of the tackifier is incorporated, the strength of the resulting film is disadvantageously decreased. Moreover, when a special resin having self-tackiness is used, the cost of the film is disadvantageously high becuase such specific resins are not economical resins which are widely used.